Circuit controlling device



Oct. 14, 1941.

w. M. scorr, JR 2,259,005

CIRCUIT CONTROLLILNG D EVICE Original Filed Aug. 27, 1938 5 Sheets-Sheet l ATTORNEY Oct. 14, 1941. w. M. scoT'r, JR 2,259,005

CIRCUIT `CONIROLLING DEVICE Original Filed Aug. 27, 1938 5 Sheets-Sheet 2 ATTORNEY Oct. 14, 1941.- w. M. sco'rT, JR

CIRCUIT CONTROLLING DEVICE Original Filed Aug. .27, 1938 5 Sheets-Sheet 3 INVENTOR M2@ ATTC-RNEY Oct. 14, 1941. w. M. scoTr, JR

` CIRCUIT CONTROLLING DEVICE Original Filed Aug. 27, 1938 v5 Sheets-Sheet 4 v INVENTQR gzamw ATTORNEY Oct. 14, 1941. w. M. sco'rT, JR

I CIRCUIT GONTROLLING DEVICE Original Filed Aug. 27, `1938 5 Sheets-Sheet 5 INVENToR .BY v Z ATroRNEY Patente'd Oct. 14, i941 -'UNI-TED STATES PATENTv OFFICE- P CIRCUIT CONTBOLLING DEVICE William M. secu, Jr., Bryn Mawr, Ps.,- auignor to I-T-Ej Circuit Breaker Company, Philadelphia, n Pa., a corporation of New Ierse! Original'appllcatlon August 27, 1938, Serial No.

1940, Serial No. 331,507

20 Claims. (Cl. 200-147) tionary contact structure of the switch or circuit-breaker, and a rigid contact member movable with and with respect to said frame for ensagement with another contact element of the stationary contact structure; more particularly,

the aforesaid 'contact elements of the stationary contact structure are connected to a blow-out coil included.- in circuit upon circuit-opening movement of said movable contact structure.

Further in accordance with my invention, a blow-out coil for a switch or circuit-breaker is disposed within a housing formed by arcing horn members which, preferably, are mechanically secured to each other and electrically connected to terminals of the'blow-out coll; more particuf l larly, the magnetic core of the coil is received by insulators which are preferably held in position by means clamping, to opposite ends of the core, polepieces secured to the' walls of an arc chute.

Further in accordance with my invention, a

'circuit-breaker or switch is provided with arc.

extinguishing means comprising` barriers of in- Divided and this application April 25.

- Fig. 2A is a rear view of the frame shown in Fig. 2.

Fig. 3 is a detail view, in side elevation, of the contact structure of the circuit-breaker of Fig. 1.

Fig. 4 is a side elevational view, partly in section, and on enlarged scale, of a blow-out and contact assembly shown in Fig. 1.

Fig. 5 is similar to Fig. 3 but with the con- 'n tacts vin open-circuit position.

Fig. 6 is a perspective view, on enlarged scale, of a bridging contact element shown in Fig. 5.

Figs. 7 to 9 inclusive, are perspective views of the components of a blow-out assembly shown in Fig. 5. l j

Fig. 10 is a front elevational view, with parts broken away, of a blow-out assembly shown in Fis. 5

Fig. l1 is a side elevational view of an insulator mente I and Ia of switchboard unit S are sealed sulatingmaterials, preferably of fibre or other f material serving as a source of arc-extinguishing gases, spaced lengthwise of the arc, portions of which are forced, as by'a blow-out coil, to elongate in loops between the barriers; more particularly, the barriers are constructed to restrict from the next lower compartment 2 by the horizontal steel barrier 8; the upper wall 4 of the compartments I, Ia is a steel plate forming the top of the unit; the rear wall of the compartment I is the removable steel cover plate l; the sides of the compartment I are formed by side plates l extending from top to bottom of the unit. 'I'he steel partition 1 isolates the two comother portions of the arc. and beyond the barriers is disposed a metallic grid structure for chilling that portion, or portions, oi the arc which expands beyond the barriers and `for chilling the aforesaid gases.

My invention further resides in the features of construction, combination, and arrangement hereinafter described and claimed.

This application is a division of my co-pending application Serial No. 227,089 nled August 27, 1938.

For an understanding of my invention, reference is made to the accompanying drawings in which:

Fig. 1 is a side view, in section, of a truck type circuit breaker and associated switchboard.

. Fig. 2 is a perspective view, on enlarged scale.

T, relays, and wiring from contacts 8 which are of the frame of the circuit-breaker unit of Fig. 1.

partments I andpIa from each other.

The upper compartments I, Ia contain auxiliary apparatus such' as potential transformers suitably mounted on the under side of that portion of the bottom of compartment or duct Ia which projects beyond the front wall of compartment 2. Other auxiliary apparatus as meters, control switches and the like, may be mounted upon the left face (Fig. 1) of panel l for observation or operation from the rear of the switchboard.

Within the compartmentv lare supported the three bus conductors I, la, Ib each wrapped in phenolic insulation, molded and cured in position and clamped in the.impregnated maple blocks I! to withstand short-circuit stresses. To each tubular bus is directly attached a support II for l `disconnect'. contacts I! whose purpose and oonstruction are described and claimed in my copending application Serial No. 331,697, led April 26, 1940. Each of the disconnect contact assemblies ls enclosed in its individual housing I3 of insulating material. ,The rear wall of compartment 2 comprises the removable panel I4 and the front wall thereof comprises the upper part of the panel I5 which is of insulating material and in which there are three staggered slots I6 for per-- the unit to facilitate its manipulation while suspended from a crane.

The frame 5I is slidable along and supported by the angle irons 52 extending across the sides of the truck and is held in position by bolts 53 (Fig. 1) which pass through the angle pieces 54 projecting rearwardly from the vrear wall 41 of the frame 5I. The brackets 55 serve to guide the frame during insertion and withdrawal of th circuit-breaker unit.

The upper face of the horizontal panel 48 and the front face of the vertical wall 41 are covered or lined vwith the panels 51, 58 of insulating material.V The strips 59 of insulating mamovable steel panel I9, contains disconnect contacts, suitably encased in insulating. housings 20, current transformer CT, and the outgoing cable connections therefrom. The housings are supported by insulators 2| from the cross brace 22 in alignment to receive the contacts 23 which pass through slots 24 in lower part of panel I5 from the rear of the breaker unit B. The duct 25 along the front face of compartment i8 may be used to encase the wires from the transformer CT vto a relay which controls tripping of the circuit-breaker.

Access to the interior of duct 25 may be had by removal of the steel panel 25a.

Extending from the front of unit S are the rails 26 for guiding .the wheels 21 of circuit breaker unit B, a .pair of lugs 28 for racking bars 205, and a dust shield 29 for theauxiliary contacts 8. The rails 26 extend upwardly from the steel base plate 30 from which also extends the cam 3| for tripping the circuit-breaker as the truck is moved toward or from the position shown in Fig. 1.

Across the open front end of each of the housings I3 extend two pivotally mounted shutters 42 of insulating material biased toward engage-- ment with each other by springs 43. The gap between the forward edges of the shutters is in alignment with the corresponding slot I6, Fig. 1,

in the panel I5 of insulation closing the front face of compartment A2 of the switchboard. When the circuit-breaker unit B is pushed into position, each of the disconnect contacts I1 enters its corresponding slot I6, separates a pair of shutters 42, and slides between the upper and lower disconnect contacts I2. When the unit B is completely withdrawn, the shutters 42, 42 within each housing close the corresponding panel slot I6 and preclude accidental contact with the-v bus conductors.

The truck unit B is a substantially rectangular structure formed by angle iron and sheet steel suitably joined as by welding. The door 44 which permits access to the circuit-breaker mechanism hereinafter described is provided near the top with a louvered opening 45 to permit escape of gases incident to circuit interruption. In the particular construction shown in Fig. 1, the top of the truck structure is closed by a sheet metal Wall 46.

The circuit-breaker and its operating mechanism is removable as a unit from the rear of the truck structure. The framework' 5I of the unit, shown in Fig, 2, comprises a sheet-steel and angle iron structure having a vertical wall 41 and a horizontal wall 48 connected and braced by gusset plates 49 having therein holes 56 to Areceive crane hooks.` Holes 50 are approxiterial projecting upwardly from horizontal panel 51, and similar strips 60 extending forwardly from vertical panel 58 form slotsfor receiving the bottom and rear edges of the panels 6I of an interpole barrier unit. The top of the barrier unit 62 is closed by panel 63 which, like its vertical panels 6I, is of insulating material. The front of the barrier unit 62 is closed by panel 64 of insulating material from the bottom to a level somewhat below that of louver 45 leaving the upper, forward parts of the isolated compartments formed by the panels 6I, 63, 51 and 58 open for discharge of arc gases. Preferably, short horizontal ledges 64a project inwardly of the compartments from or adjacent the upper edge of panel 64 to prevent the arc gases from flowing downwardly and adjacent the contact structure of the circuit-breaker.

The interpole barrier unit 62 is removable from the front of truck B by opening door 44 and pulling the barrier unit forward in the slots provided by guides 59.

The circuit-breaker shown herein is a threepole breaker but since the construction of all three poles are similar, only one need be described. Referring to Figs. 1, 3 and 5, the fixed contact assembly 65 comprises a stud 66 which passes through the sleeves 61, 68 of insulating material, at least one of which has an end 69 of reduced diameter to fit an opening in the rear vertical wall of frame 5I. By tightening nut 1U on stud 66, the two sleeves 61, 68 are forced tightly against opposite sides of the vertical wall of frame 5I. Similarly, the movable contact assembly 1I is mounted upon a stud 12 which passes through sleeves 13, 14 of insulating mateof the circuit-breaker unit B from the switchboard. The insulators 19 are secureclsto ,andji project horizontally from the rear face of the upper part of the steel wall 41 of frame 5I.

Preferablythe portion of wall 41 which supports insulators 19 lies in a plane farther to the rear than the plane of that portion of the wall from which the studs 66,12 extend. The uppermost portion of wall 41 is provided with a series of holes 80, Fig. 2, through' which pass screws 8|, Fig. 1, for securing it to the rear face of the truck. These screws, as Well as screws 53, are removed for withdrawal of the frame 5I on which all of the contact structure and operatingmechmately in line with the center of the gravity of 75 anism therefor is mounted.

v I Y 2,259,005-

Reverting to the-mounting of the contact assemblies 05 and 1|, either of two alternative arrangements may be used. In Fig. 2A the steel plate 41a is provided `with annular inserts 02 of brass or other non-magnetic material whose openings flt the reduced ends 59, 15 of the insulating sleeves 01, 13, shown in Fig. 3. Between each pair of inserts, the plate 41a is provided with a slot 83 to eliminate or minimize eddy currents. For plate 41a may be substituted a plate or casting entirely of bronze or other suitable non-magnetic material provided with openings which fit the reduced ends of the insulating sleeves 51, 13.

, The stationary contact assembly 65 and the t movable contactassembly 1| are mechanically interconnected by the insulator 04 which resists forces due to iiow of heavy currents tendingto move these assemblies away from each other. 'Ilhe insulator 05 mechanically connected to the frame member 06 of assembly 1| vand to the base plate 48 of the unit frame 5| stiilens or supports the assembly 1| against the blows or shocks incident to the opening movement of the parts of the circuit breaker.

The stationary contact assembly, Fig. l, 3 and 4, comprises the main contact member 01,.the auxiliary contact member 00, the arcing horn 09,

the arcing tip 90, and blow-out coil 9|. The auxiliary contact 80 is biased to the position shown in Fig. 3 by a spring 08a and connected by pigtail 92 to the main contact 01. A pair of links 93 on opposite sides of contacts 01, 08 support and guide the latter during its movement.

The arcing horn 99 is mechanically connected to the main Contact 81 by bolts 94,' 95, Fig. 4, which pass through sleeves 90, 91 of insulating material and clamp the front and rear ends of the horn against the plates 98, 90 of insulating material. The arcing tip 90 is supported from Athe rear face ofthe forward end of horn 99 and biased toward engagement withthe end of the horn by spring |00. Pigtail connects the movable arc horn tip 90 to the horn 89. One end of the blow-out coil 9| wound upon core |02 is held in electrical connection with main contact 81 by the bolt 95 and the other terminal of the coil is held in electrical connection with the arcing horn structure by the bolt 94.

The movable contact assembly 1i, Figs. l, 3 and 5, comprises the stationary frame member within which is plvotally mounted the movable frame member |03 connected by pigtail |04 to the stationary frame member and to the bridging contact member |05 loosely pivotally mounted in or between the sides of the movable frame' member |03. The rod |06 pivotally connected to the bridging contact member |05 near the upper end thereof passes through the split tubular structure |01 and through the plug |09 threaded into the outer end thereof. Bolts |09 may be tightened to clamp the split housing |01 upon the plug |03 and so hold it in the position affording the desired compression of spring ||0 between plug |01 and a shoulder on the rod |00. The nuts on the free end of rod |05 serve as a stop limiting the extent of its forward movement when the circuitbreaker is open.

'Ihe upper contact piece ||2 of the bridging contact member |05, Figs. 5 and 6, engages the upper main contact 81 in a vertical plane and the lower contact piece ||3 engages the lower main contact 1|a in a horizontal plane. During closure oi' the circuit-breaker, the contact ||2 engages contact 00 and causes member |05 to pivot about pin ||4 to effect wiping engagement between the lower movable,contact |3 and stationary contact 1|a. The-engagement 4of these lower contacts and continued movement offrame |03 causes member |05 to move upwardly and insure wiping engagement between the upper contact ||2 and the stationary contact 00. When the circuit-breaker is fully closed, the spring ||0 exerts a force having one component acting horizontally'to determinev the contact pressure between the upper contacts H2, 80 and another component; acting at right angles thereto to determine the contact pressure between the lower contacts ||3 and 1|a.

lTo'the upper end of movable framel member |03 is attached the arcing contact ||5 which, when the circuit breaker is closed, engages both the auxiliary contact 00 and the movable arcing horn tip 90. When the circuit-breaker is tripped the contact ||5 first separates from the auxiliary contact thus to include the blow-out coil 9| in circuit. After separation of contact H5 from the horn tip 90, the arc extends from the horn 99 to K arcing tip Ill extending from the movable arc contact ||5 until the tip |l0 moves sulciently close to the tip ||1 of a second. stationary arcing horn H0 connected by bolt 06a to the frame 05; When the arc jumps from the tip ||1 to the upper arcing horn H9, a second blow-out coil |20 is included in circuit to force the arc upwardly into the arc-chute hereinafter described.

The construction of the front blow-out assembly |2| comprising the upper and lower arcing horns H9, ||9 and coil |20 is more clearly understood from Figs. 9 to 13. When the upper horn H9, Fig. 9, and the lower horn ||1, Fig. 7, are in their assembled position, they provide a housing or casing for the blow-out coil |20 (Fig. 13)A one terminal |22 of which is held in electrical contact with the upper horn ||9 by bolts, not shown, which pass through insulating sleeves and washers, through holes |23 in the lower horn H8, and holes |24 in terminal |22 to thread into holes in the under face of block |25 integral with the upper horn IIS. similarly, the other terminal |25 of the blow-out coil |20 is held in electrical contact with the lower horn ||8 by bolts |21 which pass through insulating sleeves and washers, holes |28 in the lower horn H8, and holes |29 in' coil terminal |26 to thread into holes in the under face of projection |30 of the upper horn 'Ihe core |3| for the blow-out coil is preferably formed by winding a strip of thin sheet iron to 'form a cylinder received by a tube |32 of insulat- |33a through the insulators |33 received by annular recesses |34 in the sides of the upper and lower horn asembly. The inner faces of the insulators, Fig. 13, are out of contact with and appreciably spaced from the arcing horns except adjacent the core. The front blow-out assembly is held to frame by bolt 86a which holds the extension ||8a of the lower horn between the clamping plat|35 (Fig. 13) and the extension 06h. of the frame 80.

In the preferred arrangement shown, the front blow-out assembly is removable as a unit with the arc-chute assembly |36 (Figs. l, 13 and 14). The bolt |31 which passes through the core |3| o f the front blow-out coil |20 clamps it against the pole pieces |38 held against the outside faces of the side panels |39 of the arc chute. The pole pieces |40 for the rear blow-out coil 9| are also held.

From the tripping lever Ill is suspended the rod which extends through the base of the truck in line with the cam Il on the base of the switchboard to trip the circuit breaker, if it be closed, as the truck is pulled out of or pushed into' the switchboard. Y

The bar 202 pivotally suspended from arm lila on the operating shaft |58 of the circuit-breaker is utilized to operate the auxiliary switches 203 mounted upon the panel 20| suitably mounted in Vthe lower compartment of the truck. These switches may be used to operate signal lights or perform other control functions in accordance with the positionvof the circuit-breaker.

The truck unit is locked in its innermost or normal position by a pair of bars 205 each having a hooked end which drops over and engages the pin 20| of one of the pair of abutment' members 20 attached to the front face of each of the switchboard units SI-Sl. The other end of each bar 205 is pivotally connected to an arm secured to shaft |98 to which is secured a second notched disk, not shown, accessible through the opening in the door 44 of the truck.

The manner in which this second disk is operated to move the truck from the switchboard to and from a test-position or to and from a fully withdrawn position is described in my application Serial No. 251,500 filed January 18,- 1939, a division of aforesaid application Serial No. 227,089. September 24, IMI

What I claim is:

l. A circuit breaker comprising a rigid frame,

a contact structure supported therefrom, a rigid contact arm movable between open and closed circuit positions and supported from said frame, an inexible contact member for engaging said contact structure loosely pivoted to said arm for movement with and with respect to said arm, a secondary contact electricallyI connected to said contact structure and mounted for movement relative thereto, and a secondary contact immovably secured to said arm for movement therewith into and out of engagement with said first-named secondary contact.

2. A circuit breakercomprising a rigid frame, y a pair of stationary contact structures supported therefrom, a rigid contact arm movable between open and closed circuit positions, an inflexible contact member for bridging said contact structures loosely pivoted to said arm foi-'movement with and with respect to said arm, a secondary contact electrically connected to one of said contact structures and mountedfor movement relative thereto, and a secondary contact immovably secured to said arm for movement therewith into and out of engagement with said ilrstnamed secondary contact.

3. A circuit breaker comprising a rigid frame, a stationary contact structure supported therefrom, a rigid contact armmovable between open and closed-circuit positions and supported from said frame, an inflexible contact member for engaging said contact structure loosely pivoted to said arm for movement with and with respect to said arm, a secondary contact electrically connected to said contact structure and mounted for movement relative thereto, a secondary contact immovably secured to said arm for movement therewith into and out of engagement with said first-named secondary contact, and means for biasing said secondary contacts toward each other supplemented by the biasing eileet of current traversing them'.

4. A circuit breaker comprising a rigid frame,

a pair of stationary contact structures supported therefrom, a rigid contact arm movable between open and closed circuit positions, an inexible contact member for bridging said contact structures loosely pivoted to said arm for movement.

with and with respect to said arm, a secondary contact electrically connected to one of said contact structures and mounted for movement relative thereto, a'secondary contact immovably secured to said arm for movement therewith into and out of engagement with said first-named 'secondary contact, and means for biasing said .pivoted to said arm for movement with and with respect to it, a secondary contact mounted for movement adjacent said stationary contact structure, a blowout coil supported from said stationary contact structure and electrically connecting it to said secondary contact, and a secondary contact rigidly secured to said arm for movement therewith into and out of engagement with the rst-named secondary contact.

6. A circuit interrupter comprising a rigid frame, a pair of stationary contacts supported from said frame, a rigid contact arm electrically connected to one of said contacts, a rigid pivotal mounting for said contact arm, a contact member for bridging said stationary contacts loosely pivotedV to said arm for movement with and with respect to it, a secondary contact mounted for movement adjacent the other of said stationary contacts, a blowout coil supported by said other of said stationary contacts and electrically connecting it to said secondary contact, and a secondary contact rigidly secured to said arm for movement therewith into and out of engagement with said first-named secondary circuit.

7. A circuit interrupter comprising a rigid frame, a contact assembly supported from said frame and comprising a main Contact, an auxiliary contact movably supported thereon and directly electrically connected thereto, a blowout coll, and a second auxiliary contact movably supported from said main contact and electrically connected thereto through said blowout coil, a second contact assembly supported from said frame comprising a second main contact, a rigid contact arm electrically connected to said second main contact, a bridging contact loosely pivoted to said arm and movable therewith to engage both of said main contacts, and a, contact rigidly secured to said arm for engaging both of said auxiliary contacts.

8. An arc-chute assembly removable asa unit from a circuit breaker and comprising side panels, spaced metal plates supported by and extending between said side panels, spaced plates of insulation supported from and extending parallel to said side panels within the arc chute, and a blowout 'coil and arcing horn unit supported between said side panels to force the arc successively to engage said plates of insulation and said metal plates.

9.` A circuit breaker comprising a frame, stationary contacts supported from said frame, a blowout coil and arc-horn assembly mounted on one of said stationary contacts, and an arc-chute assembly removable as a unit from the circuit breaker comprising sides ior disengageably connecting the chute to said coil and horn assembly, and a second blowout coil and arc-horn assembly disengageably connected to the other of said n stationary contacts.

10. A blowout coil and arc-horn assembly comprising two horn members having therein reaeeaooc coil by the arc drawn between said arcing con-l tacts by movement of said movable main contactv structure.

16. A circuit-controlling device having contacts normally in engagement to close a circuit,

- structure extending longitudinally of the arc incesses` forming a coil housing, a blowout coil members having complementary internal recesses forming a coil housing, a blowout coil within said housing, a core for said coil, disk insulators for receiving the opposite ends oi said core, an arc chute having sides oi insulating vmaterial and pole plates secured to the external faces thereof, and means for clamping said pole plates to the opposite ends of said core and to hold saidinsulators in position on said core between said sides oi. the arc chute.

13. A circuit controlling device having contacts normally in engagament to close a circuit, a plurality of plates of insulating material disposed substantially parallel to each other and to the longitudinal axis of the arc incident to separa tion of said contacts, means forcing the arc to split and pass between said closely spaced plates, and a plurality of metallic plates beyond said plates of insulating material disposed substan- 'tially parallel to each other and substantially at right angles to said axis of the arc.

14. A circuit-breaker comprising a rigid frame, a contact structure xedly supported therefrom, a secondary contact electrically connected to said contact structure for movement relative. thereto,

a movable rigid arm supported from said frame, a secondary contact immovably secured to said arm for movement therewith to engage and effect Y movement of said rst-named'secondary contact said contact structure loosely pivoted upon said arm for movement bodily with respect to said arm and to said first-named secondary contact structure during final circuit-closing and initial circuit-opening movements of said arm.

15. A circuit-breaker comprising stationary main contact structure, a movable main contact structure normally in circuit-closing engagement with said stationary main contact structure, stationary arcing contacts adjacent the path of movement of said movable main contact structure, a blow-out coil connected between one of said arcing contacts and said stationary main contact structure for inclusion in series with the arc between and incident to initial separation of said main contact structures, and a second blowout coil connected between said second arcing contact and said movable main contact structurefor inclusion in series with said rst blow-out normally in engagement to close a circuit, struccident to separation of said contacts to dene a longitudinally restricted passage for said arc,'

means for forcing the arc through said passage restricted longitudinally thereof, an expansion chamber beyond said structure to receive and chill by expansion arc gases issuing from said restricted passage, and metallic grid structure for chilling the expanded gases as they pass from said chamber.

17. A circuit controlling device having contacts tures of insulating material spaced from each other lengthwise of the arc incident to separation of said contacts to provide between said structures a substantiallynnrestricted passagev for an intermediate portion oi the arc and constructed to provide transversely restricted passages for other portions of the arc, and means for forcing said intermediate portion of the arc to move as a loop iny said unrestricted passage.

18. A circuit controlling device having contacts normally in engagement to close a circuit, structures of insulating material spaced from each other lengthwise of the arc incident to separation of said contacts to provide between said structures a substantially unrestricted passage and constructed to provide transversely restricted passages extending lengthwise of the arc, an exlDansion chamber in communication with said restructures a substantially unrestricted passage for an intermediate portion of the arc and constructed to provide transversely restricted passages or other portions oi the arc, and metallic grid structure beyond said structures for chilling v any portion of the arc reaching -it through said restricted orunrestricted passages. 20. A circuit controlling device having contacts normally in engagement to close a circuit, structures of insulating material serving as a source of de-ionizing gases spaced from each other lengthwise of the arc incidentto separation of said contacts to provide a substantially unrestricted passage for an intermediate portion of the arc and said gases and constructed to provide transversely restricted passages for other' portions of the are and said gases, metallic grid structure disposed beyond said restricted and un vrestricted passages for chilling said gases and any portion of the arc reaching it through said pas*- sage, and means for forcing the arc from said contacts toward said grid structure through said paths.

'. IVI. SCO'I'I'. JR. 

